| In view of the existing concrete simply-supported double-T railway bridge in the increasing speed of train and axle load of freight train leading to the problems of large bridge transverse amplitude,a retrofit measure with adding steel braces between web plates for the railway bridge is proposed in this paper.This strengthening method can effectively strengthen the connection between the T beams,and enhance the lateral stiffness of the beam,which makes the whole structure form a steel concrete composite structure,and the stress performance is more superior.This reinforcement method is simple in construction,and can shorten the construction period.It also doesn’t interrupt the normal operation of the train,and has little effect on the vertical performance and substructure of the bridge.The static performance of the bridge and dynamic interaction between train and bridge before and after strengthening with adding steel braces are studied through the finite element analysis software ANSYS and multi-body dynamics software Universal Mechanism(UM).The main works of this thesis are as following:(1)Based on the finite element software ANSYS,the 32m cross standard double-T beam model was established,and the effects of 3 kinds of brace arrangement form with different number of braces and the section area are analyzed.And the brace arrangement is optimized.(2)The bridge model before and after strengthening is imported to UM software for vehicle bridge coupling simulation.In order to evaluate the effect of the bridge,the dynamic response of the passenger train and freight train at different speed levels is analyzed.(3)The mechanism of bridge resonance and vibration suppression is analyzed.The resonance response of the bridge before and after strengthening is proposed with numerical simulation,and the correctness of the theoretical calculation results is proved. |
